CN220895763U

CN220895763U - Cylindrical battery monomer, battery and electric equipment

Info

Publication number: CN220895763U
Application number: CN202322344594.5U
Authority: CN
Inventors: 程兴; 苏华圣; 金义矿; 伍永彬; 牛少军
Original assignee: Contemporary Amperex Technology Co Ltd
Current assignee: Contemporary Amperex Technology Co Ltd
Priority date: 2023-08-30
Filing date: 2023-08-30
Publication date: 2024-05-03
Anticipated expiration: 2033-08-30

Abstract

The application provides a cylindrical battery monomer, a battery and electric equipment. The cylindrical battery cell includes a housing including a first half and a second half, and an electrode assembly. The portion of the middle section of the housing to one end of the housing is a first half area, and the portion of the middle section of the housing to the other end of the housing is a second half area along the first direction. The first half area and the second half area are both provided with at least one pressure relief mechanism, and the pressure relief mechanism can be used for opening pressure relief when the internal pressure or the temperature of the battery monomer reaches a threshold value. The electrode assembly is accommodated in the case. The electrode assembly includes a body portion and a tab connected to the body portion. The main body portion has a center hole penetrating both ends of the main body portion in a first direction. The central hole communicates the interior space of the first half with the interior space of the second half. The aperture of the central hole is D, the outer diameter of the main body part is D, and D/D is more than or equal to 10% and less than or equal to 30%. Because the centre bore is great, gas can flow to relief mechanism from center Kong Xunsu during the pressure release, and the reliability is high.

Description

Cylindrical battery monomer, battery and electric equipment

Technical Field

The application relates to the field of batteries, in particular to a cylindrical battery monomer, a battery and electric equipment.

Background

Batteries are widely applied in the field of new energy, such as electric automobiles, new energy automobiles and the like, and the new energy automobiles and the electric automobiles have become new development trends of automobile industry. The development of battery technology is to consider various design factors, such as battery life, energy density, discharge capacity, charge-discharge rate, and other performance parameters. In addition, the reliability of the battery cells needs to be considered. However, the reliability of the current cylindrical battery cell is poor.

Disclosure of utility model

The embodiment of the application aims to provide a cylindrical battery monomer, a battery and electric equipment, which aim to solve the problem of poor reliability of the battery in the related technology.

In a first aspect, an embodiment of the present application provides a cylindrical battery cell, where the cylindrical battery cell includes a housing and an electrode assembly, the housing includes a first half area and a second half area, a portion from a middle section of the housing to one end of the housing is the first half area, and a portion from the middle section of the housing to the other end of the housing is the second half area, where at least one pressure release mechanism is provided in each of the first half area and the second half area, and the pressure release mechanism is configured to be opened when an internal pressure or temperature of the cylindrical battery cell reaches a threshold value, so as to release the pressure inside the cylindrical battery cell; the electrode assembly is accommodated in the shell, the electrode assembly comprises a main body part and a tab, the tab is connected to the main body part, the main body part is provided with a central hole, the central hole penetrates through two ends of the main body part along the first direction, the central hole is communicated with the inner space of the first half area and the inner space of the second half area, the aperture of the central hole is D, the outer diameter of the main body part is D, and the requirements are met: D/D is more than or equal to 10% and less than or equal to 30%.

In the technical scheme, the first half area and the second half area of the cylindrical battery cell are both at least provided with the pressure release mechanism, gas in the electrode assembly can flow to the pressure release mechanism located in the first half area and the pressure release mechanism located in the second half area through the central hole, compared with the prior art that the gas needs to flow from one end of the shell to the other end, the pressure release path is shorter, the quick pressure release is facilitated, and the risk of ignition and explosion of the cylindrical battery cell is reduced. In addition, through making the aperture of the centre bore of electrode assembly and the external diameter of main part be greater than or equal to 10% and be less than or equal to 30%, not only can make the centre bore of this electrode assembly great, the surplus space in the shell is bigger, and the atmospheric pressure in the shell is less relatively, and during the pressure release, gas can flow to relief mechanism from center Kong Xunsu, and the pressure release rate is fast, is favorable to reducing the risk that cylinder battery monomer fires, explodes, is favorable to promoting the reliability of cylinder battery monomer, can also make cylinder battery monomer have great energy density.

As an alternative technical scheme of the embodiment of the application, the D/D is more than 17% and less than or equal to 25%.

In the above technical scheme, through making the aperture of the centre bore of electrode assembly and the external diameter of main part be greater than 17% and be less than or equal to 25%, not only enable this electrode assembly's centre bore bigger, the space that remains in the shell is bigger, the atmospheric pressure in the shell is smaller relatively, during the pressure release, gas can flow to relief mechanism from center Kong Xunsu, the pressure release speed is faster, be favorable to reducing the risk that cylinder battery monomer fires, explodes, be favorable to promoting the reliability of cylinder battery monomer, still enable cylinder battery monomer to have bigger energy density.

As an alternative solution of the embodiment of the present application, the housing has a first end wall, a second end wall and a side wall, where the first end wall is located in the first half area, the second end wall is located in the second half area, the first end wall and the second end wall are opposite to each other along the first direction, and the side wall is enclosed around the first end wall and the second end wall; the part of the side wall located in the first half area and the part of the side wall located in the second half area are both provided with at least one pressure relief mechanism.

In the above technical scheme, if the lateral wall is located the part of first half district and the lateral wall is located the part of second half district and all is provided with pressure release mechanism, the inside discharge medium of shell can be followed the lateral wall discharge of shell, reduces the risk that discharge medium caused the destruction to the external part of connecting in the free tip of cylinder battery, is favorable to promoting the free reliability of cylinder battery.

As an alternative solution of the embodiment of the present application, a portion of the side wall located in the first half area and/or a portion of the side wall located in the second half area is provided with a plurality of the pressure relief mechanisms.

In the technical scheme, through setting up a plurality of relief mechanisms, when the free internal pressure of cylinder battery or temperature reach the threshold value, a plurality of relief mechanisms can open the pressure release, and the pressure release speed is faster, is favorable to reducing the free risk of firing of cylinder battery, explosion, is favorable to promoting the free reliability of cylinder battery.

As an optional technical solution of the embodiment of the present application, a plurality of pressure relief mechanisms are distributed at intervals along a circumferential direction of the housing, and the plurality of pressure relief mechanisms include a first pressure relief mechanism and a second pressure relief mechanism, where an opening pressure of the first pressure relief mechanism is greater than an opening pressure of the second pressure relief mechanism.

In the above technical scheme, the opening pressure of the first pressure release mechanism is greater than the opening pressure of the second pressure release mechanism, the anti-damage capability of the first pressure release mechanism is greater than the anti-damage capability of the second pressure release mechanism, when the pressure or the temperature inside the shell reaches a threshold value, the second pressure release mechanism is opened to realize pressure release, and at this time, the first pressure release mechanism cannot be opened. The setting of first release mechanism can balance the deflection of lateral wall when setting up second release mechanism for the shape of lateral wall is more regular, and the circularity of lateral wall is higher, is favorable to improving the free assembly quality of cylinder battery, thereby improves the free reliability of cylinder battery.

As an alternative solution of the embodiment of the present application, a plurality of the pressure relief mechanisms are uniformly distributed along the circumferential direction of the housing.

In the above technical scheme, through making a plurality of relief mechanisms follow the circumference evenly distributed of shell, like this, when setting up first relief mechanism and second relief mechanism, the atress of lateral wall is more balanced, and the shape of lateral wall is more regular, and the circularity of lateral wall is higher, is favorable to improving the free assembly quality of cylinder battery to improve the free reliability of cylinder battery.

As an alternative solution of the embodiment of the present application, the housing is provided with a first score groove, and the first score groove defines the first pressure release mechanism; the housing is provided with a second score groove defining the second pressure relief mechanism, the residual thickness of the first score groove being greater than the residual thickness of the second score groove.

In the technical scheme, the first pressure relief mechanism and the second pressure relief mechanism are formed on the shell in a mode of forming the first score groove and the second score groove, so that the first pressure relief mechanism and the shell are of an integrated structure, and the second pressure relief mechanism and the shell are of an integrated structure, and the integrity is better. The residual thickness of the first notch groove is larger than that of the second notch groove, the anti-damage capability of the shell at the position of the first notch groove is larger than that of the shell at the position of the second notch groove, when the pressure or temperature inside the shell reaches a threshold value, the side wall is split along the second notch groove, pressure release is achieved, the side wall cannot be split along the first notch groove at this time, the deformation of the side wall during forming of the second notch groove can be balanced through the arrangement of the first notch groove, the shape of the side wall is more regular, the roundness of the side wall is improved, the assembly quality of a battery cell is improved, and the reliability of the battery cell is improved.

As an optional technical solution of the embodiment of the present application, the depth of the first score groove is smaller than the depth of the second score groove, so that the residual thickness of the first score groove is greater than the residual thickness of the second score groove.

In the above technical solution, the depth of the second score groove is greater than the depth of the first score groove, and then the residual thickness of the second score groove is smaller than the residual thickness of the first score. Thus, the anti-damage capability of the first pressure relief mechanism is larger than that of the second pressure relief mechanism, and the detonation pressure of the first pressure relief mechanism is larger than that of the second pressure relief mechanism.

As an optional technical solution of the embodiment of the present application, the depth of the second score groove is H ₁, which satisfies the following requirements: h ₁ is less than or equal to 0.01mm and less than or equal to 4.5mm.

In the technical scheme, the depth of the second notch groove is between 0.01 and 4.5mm, so that the second pressure release mechanism is easy to open for pressure release, and the side wall has enough strength.

As an optional technical solution of the embodiment of the present application, the groove width of the second score groove is D ₁, which satisfies the following requirements: d ₁ is more than or equal to 0.01mm and less than or equal to 100mm.

In the technical scheme, the groove width of the second notch groove is between 0.01 and 100mm, so that the second pressure release mechanism is easy to open and release pressure, and the side wall has enough strength. In addition, the groove width of the second notch groove is larger, and a larger opening can be opened, so that pressure can be relieved rapidly, and the reliability of the cylindrical battery monomer is improved.

As an optional technical solution of the embodiment of the present application, along the extending direction of the second score groove, the length of the second score groove is L ₁, which satisfies the following requirements: l ₁ mm to 250mm.

In the technical scheme, the length of the second score groove is between 1 and 250mm, so that the second pressure release mechanism is easy to open and release pressure, and the side wall has enough strength. In addition, the length of the second notch groove is larger, and a larger opening can be opened, so that pressure can be relieved rapidly, and the reliability of the cylindrical battery monomer is improved.

As an alternative solution of the embodiment of the present application, the volume of the second score groove is V ₁, the volume of the outer surface of the side wall is V ₂, and the volume of the inner surface of the side wall is V ₃, which satisfies the following requirements: v ₁/(V₂-V₃) is less than or equal to 0.1.

In the technical scheme, V ₁/(V₂-V₃) is less than or equal to 0.1, the shell has higher strength, the electrode assembly in the shell can be effectively protected, and when external impact is received, the second pressure release mechanism is not easy to open by mistake, so that the reliability of the cylindrical battery monomer is improved.

As an optional technical solution of the embodiment of the present application, the casing is provided with a second score groove, the second score groove defines the second pressure release mechanism, the minimum residual thickness of the second score groove is C ₁, and the thickness of the side wall is C ₂, which satisfies the following requirements: c ₁/C₂ is more than or equal to 0.1 and less than or equal to 0.9.

In the technical scheme, the ratio of the minimum residual thickness of the second score groove to the residual thickness of the side wall is between 0.1 and 0.9, so that the second pressure release mechanism can be easily opened for pressure release, and the side wall has enough strength.

As an alternative technical scheme of the embodiment of the application, C ₁/C₂ is more than or equal to 0.3 and less than or equal to 0.7.

In the technical scheme, through enabling C ₁/C₂ to be more than or equal to 0.3 and less than or equal to 0.7, the strength of the side wall is better, and the second pressure release mechanism is not easy to open by mistake under the action of external force.

As an optional technical solution of the embodiment of the present application, the first pressure relief mechanism and the second pressure relief mechanism are alternately arranged along the circumferential direction of the housing.

In the technical scheme, the first pressure relief mechanism and the second pressure relief mechanism are alternately arranged in the circumferential direction of the shell, so that the stress of the side wall is more uniform when the first pressure relief mechanism and the second pressure relief mechanism are arranged, the shape rule of the side wall is favorably maintained, and the roundness of the side wall is higher.

As an optional technical solution of the embodiment of the present application, along the first direction, a minimum distance between the pressure release mechanism and one end of the housing, which is closer to the pressure release mechanism, is L ₂, and a length of the housing is L ₃, where the requirements are satisfied: l ₂/L₃ is more than or equal to 0.3.

In the technical scheme, the minimum distance between the pressure release mechanism and one end of the shell, which is closer to the pressure release mechanism, is greater than or equal to 0.3 times of the length of the shell, so that the distance between the pressure release mechanism and one end of the shell is larger, and the roundness of the end part of the pressure release mechanism is not easy to influence when the pressure release mechanism is arranged, thereby being beneficial to improving the assembly quality of the cylindrical battery monomers, and further improving the reliability of the cylindrical battery monomers.

As an alternative technical solution of the embodiment of the present application, the housing is provided with a through hole, and the pressure relief mechanism is mounted on the housing and blocks the through hole.

In the technical scheme, when the cylindrical battery cell body is out of control, the pressure release mechanism can open the through hole under the action of the air pressure or high-temperature air of the cylindrical battery cell body, so that the air in the cylindrical battery cell body is allowed to be discharged out of the shell, and pressure release is realized.

As an alternative technical scheme of the embodiment of the application, the pressure relief mechanism is a filling layer filled in the through hole.

In the technical scheme, when the cylindrical battery cell body is out of control, the filling layer can open the through hole under the action of the air pressure or high-temperature air of the cylindrical battery cell body, so that the air in the cylindrical battery cell body is allowed to be discharged out of the shell, and pressure relief is realized.

As an optional technical solution of the embodiment of the present application, along the circumferential direction of the housing, the maximum size of the pressure relief mechanism is D ₂, and the circumference of the housing is N, which satisfies: d ₂/N is more than or equal to 5% and less than or equal to 25%.

In the technical scheme, the maximum size of the pressure relief mechanism along the circumferential direction of the shell is limited to 0.05-0.25 time of the circumferential length of the shell, so that the pressure relief mechanism is convenient to process, the processed pressure relief mechanism is easy to open and relieve pressure, and the shell can have enough strength.

As an optional technical solution of the embodiment of the present application, along the first direction, a maximum size of the pressure relief mechanism is L ₄, and a length of the housing is L ₃, which satisfies: l ₄/L₃% to 25%.

In the technical scheme, the maximum size of the pressure release mechanism along the first direction is limited to be 0.05-0.25 time of the length of the shell, so that the pressure release mechanism can be opened easily to release pressure, the shell has enough strength, and the opening opened when the pressure release mechanism releases pressure is larger, thereby realizing quick pressure release.

As an alternative solution of the embodiment of the present application, the electrode assembly is a wound electrode assembly.

In the above-described aspects, the pressure relief effect is better in the wound electrode assembly than in the laminated electrode assembly because the pressure relief is more dependent on the center hole, by making the ratio of the aperture of the center hole of the electrode assembly to the outer diameter of the main body part 10% or more.

In a second aspect, embodiments of the present application also provide a battery comprising a cylindrical cell according to any one of the above.

In a third aspect, an embodiment of the present application further provides an electrical apparatus, where the electrical apparatus includes the cylindrical battery cell in any one of the foregoing aspects.

Drawings

In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings that are needed in the embodiments will be briefly described below, it being understood that the following drawings only illustrate some embodiments of the present application and therefore should not be considered as limiting the scope, and other related drawings may be obtained according to these drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic illustration of a vehicle according to some embodiments of the present application;

Fig. 2 is an exploded view of a battery provided in some embodiments of the present application;

Fig. 3 is a schematic structural diagram of a cylindrical battery cell according to some embodiments of the present application;

fig. 4 is an exploded view of a cylindrical battery cell according to some embodiments of the present application;

FIG. 5 is a schematic top view of a body portion according to some embodiments of the present application;

FIG. 6 is a schematic front view of a sidewall according to some embodiments of the present application;

FIG. 7 is a cross-sectional view taken at the A-A position of FIG. 6;

FIG. 8 is a schematic front view of a sidewall according to other embodiments of the present application;

fig. 9 is a cross-sectional view of the B-B position of fig. 8.

Icon: 10-a box body; 11-a first part; 12-a second part; 20-a cylindrical battery cell; 21-a housing; 211-first half region; 212-second half; 213-a first end wall; 214-sidewalls; 2141-a first score groove; 2142-a second score groove; 2143-a through hole; 2144-a filler layer; 215-a second end wall; 216-a housing; 217-end cap; 22-a pressure release mechanism; 221-a first pressure relief mechanism; 222-a second pressure relief mechanism; 23-an electrode assembly; 231-a body portion; 2311-a central hole; 232-electrode lugs; 24-electrode terminals; 100-cell; 200-a controller; 300-motor; 1000-vehicle; w-middle section.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the embodiments of the present application more apparent, the technical solutions of the embodiments of the present application will be clearly described below with reference to the accompanying drawings in the embodiments of the present application, and it is apparent that the described embodiments are some embodiments of the present application, but not all embodiments of the present application. All other embodiments, which can be made by those skilled in the art based on the embodiments of the application without making any inventive effort, are intended to be within the scope of the application.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application belongs; the terminology used in the description of the application herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the application; the terms "comprising" and "having" and any variations thereof in the description of the application and the claims and the description of the drawings above are intended to cover a non-exclusive inclusion. The terms first, second and the like in the description and in the claims or in the above-described figures, are used for distinguishing between different objects and not necessarily for describing a particular sequential or chronological order.

Reference in the specification to "an embodiment" means that a particular feature, structure, or characteristic described in connection with the embodiment may be included in at least one embodiment of the application. The appearances of such phrases in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments mutually exclusive of other embodiments.

In the description of the present application, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "attached" are to be construed broadly, and may be, for example, fixedly connected, detachably connected, or integrally connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present application can be understood by those of ordinary skill in the art according to the specific circumstances.

The term "and/or" in the present application is merely an association relation describing the association object, and indicates that three kinds of relations may exist, for example, a and/or B may indicate: a exists alone, A and B exist together, and B exists alone. In the present application, the character "/" generally indicates that the front and rear related objects are an or relationship.

In the embodiments of the present application, the same reference numerals denote the same components, and detailed descriptions of the same components are omitted in different embodiments for the sake of brevity. It should be understood that the thickness, length, width, etc. dimensions of the various components in the embodiments of the application shown in the drawings, as well as the overall thickness, length, width, etc. dimensions of the integrated device, are merely illustrative and should not be construed as limiting the application in any way.

The term "plurality" as used herein refers to two or more (including two).

In the present application, the cylindrical battery cell may include a lithium ion secondary battery cell, a lithium ion primary battery cell, a lithium sulfur battery cell, a sodium lithium ion battery cell, a sodium ion battery cell, or a magnesium ion battery cell, which is not limited in the embodiment of the present application. The battery cell may be in a cylindrical shape, a flat shape, a rectangular parallelepiped shape, or other shapes, which is not limited in this embodiment of the application.

Reference to a battery in accordance with an embodiment of the application is to a single physical module that includes one or more cylindrical cells to provide higher voltage and capacity. For example, the battery referred to in the present application may include a battery module or a battery pack, or the like. The battery typically includes a housing for enclosing one or more cylindrical battery cells. The case can prevent liquid or other foreign matters from affecting the charge or discharge of the cylindrical battery cell to a certain extent.

The cylindrical battery monomer comprises an electrode assembly and electrolyte, wherein the electrode assembly consists of a positive plate, a negative plate and a separation membrane. The cylindrical battery cell mainly relies on metal ions to move between the positive electrode plate and the negative electrode plate to work. The positive plate comprises a positive electrode current collector and a positive electrode active material layer, wherein the positive electrode active material layer is coated on the surface of the positive electrode current collector, the positive electrode current collector without the positive electrode active material layer protrudes out of the positive electrode current collector coated with the positive electrode active material layer, and the positive electrode current collector without the positive electrode active material layer is used as a positive electrode lug. Taking a lithium ion battery as an example, the material of the positive electrode current collector may be aluminum, and the positive electrode active material may be lithium cobaltate, lithium iron phosphate, ternary lithium, lithium manganate or the like. The negative electrode sheet comprises a negative electrode current collector and a negative electrode active material layer, wherein the negative electrode active material layer is coated on the surface of the negative electrode current collector, the negative electrode current collector without the negative electrode active material layer protrudes out of the negative electrode current collector coated with the negative electrode active material layer, and the negative electrode current collector without the negative electrode active material layer is used as a negative sub-tab. The material of the negative electrode current collector may be copper, and the negative electrode active material may be carbon, silicon, or the like. In order to ensure that the high current is passed without fusing, the number of positive sub-tabs is multiple and stacked together, and the number of negative sub-tabs is multiple and stacked together. The material of the separator may be PP (polypropylene) or PE (polyethylene). In addition, the electrode assembly may be a roll-to-roll structure or a lamination structure, and embodiments of the present application are not limited thereto.

Currently, the more widely the battery is used in view of the development of market situation. The battery is not only applied to energy storage power supply systems such as hydraulic power, firepower, wind power and solar power stations, but also widely applied to electric vehicles such as electric bicycles, electric motorcycles, electric automobiles, and the like, as well as a plurality of fields such as military equipment, aerospace, and the like. With the continuous expansion of the battery application field, the market demand thereof is also continuously expanding.

The development of battery technology is to consider various design factors, such as battery life, energy density, discharge capacity, charge-discharge rate, and other performance parameters. In addition, the reliability of the battery needs to be considered. However, the reliability of the current battery is poor.

For the battery monomer, in order to guarantee the reliability of the battery monomer, a pressure release mechanism is arranged on a shell of the battery monomer in the prior art, and when the battery monomer is in thermal runaway, the pressure release mechanism is opened to release the pressure in the battery monomer so as to reduce the risks of explosion and ignition of the battery monomer.

However, for the single cylinder battery, the pressure release mechanism is arranged on the single cylinder battery end cover, when the single cylinder battery is depressurized, gas flows from one end far away from the end cover to the end cover and is depressurized through the pressure release mechanism on the end cover, the pressure release path is longer, the pressure release rate is lower, the single cylinder battery is difficult to depressurize, the single cylinder battery is still easy to fire and explode, and the single cylinder battery is poor in reliability.

In view of this, embodiments of the present application provide a cylindrical battery cell including a housing and an electrode assembly. The housing includes a first half section and a second half section, and along a first direction, a portion of the housing from the middle section of the housing to one end of the housing is the first half section, and a portion of the housing from the middle section of the housing to the other end of the housing is the second half section. The first half area and the second half area are both provided with at least one pressure relief mechanism, and the pressure relief mechanism is configured to be opened when the internal pressure or temperature of the cylindrical battery cell reaches a threshold value so as to relieve the pressure inside the cylindrical battery cell. The electrode assembly is accommodated in the case. The electrode assembly includes a body portion and a tab connected to the body portion. The main body part is provided with a central hole, the central hole penetrates through two ends of the main body part along the first direction, and the central hole is communicated with the inner space of the first half area and the inner space of the second half area. The aperture of the central hole is D, the outer diameter of the main body part is D, and the requirements are satisfied: D/D is more than or equal to 10% and less than or equal to 30%.

The first half area and the second half area of the cylindrical battery monomer are both provided with at least one pressure release mechanism, gas in the electrode assembly can flow to the pressure release mechanism located in the first half area and the pressure release mechanism located in the second half area through the central hole, compared with the prior art that the gas needs to flow from one end of the shell to the other end, the pressure release path is shorter, the quick pressure release is facilitated, and the risk of ignition and explosion of the cylindrical battery monomer is reduced. In addition, through making the aperture of the centre bore of electrode assembly and the external diameter of main part be greater than or equal to 10% and be less than or equal to 30%, not only can make the centre bore of this electrode assembly great, the surplus space in the shell is bigger, and the atmospheric pressure in the shell is less relatively, and during the pressure release, gas can flow to relief mechanism from center Kong Xunsu, and the pressure release rate is fast, is favorable to reducing the risk that cylinder battery monomer fires, explodes, is favorable to promoting the reliability of cylinder battery monomer, can also make cylinder battery monomer have great energy density.

The technical scheme described by the embodiment of the application is suitable for the battery and the electric equipment using the battery.

The electric equipment can be vehicles, mobile phones, portable equipment, notebook computers, ships, spacecrafts, electric toys, electric tools and the like. Spacecraft including airplanes, rockets, space planes, spacecraft, and the like; the electric toy includes fixed or mobile electric toys, such as a game machine, an electric car toy, an electric ship toy, and an electric airplane toy; power tools include metal cutting power tools, grinding power tools, assembly power tools, and railroad power tools, such as electric drills, electric grinders, electric wrenches, electric screwdrivers, electric hammers, impact drills, concrete shakers, and electric planers, among others. The embodiment of the application does not limit the electric equipment in particular.

For convenience of description, the following embodiments take the electric device as the vehicle 1000 as an example.

Referring to fig. 1, fig. 1 is a schematic structural diagram of a vehicle 1000 according to some embodiments of the application. The vehicle 1000 may be a fuel oil vehicle, a gas vehicle or a new energy vehicle, and the new energy vehicle may be a pure electric vehicle, a hybrid vehicle or a range-extended vehicle. The battery 100 is provided in the interior of the vehicle 1000, and the battery 100 may be provided at the bottom or the head or the tail of the vehicle 1000. The battery 100 may be used for power supply of the vehicle 1000, for example, the battery 100 may be used as an operating power source of the vehicle 1000. The vehicle 1000 may also include a controller 200 and a motor 300, the controller 200 being configured to control the battery 100 to power the motor 300, for example, for operating power requirements during start-up, navigation, and travel of the vehicle 1000.

In some embodiments of the present application, battery 100 may not only serve as an operating power source for vehicle 1000, but may also serve as a driving power source for vehicle 1000, instead of or in part instead of fuel oil or natural gas, to provide driving power for vehicle 1000.

Referring to fig. 2, fig. 2 is an exploded view of a battery 100 according to some embodiments of the present application. The battery 100 includes a case 10 and a cylindrical battery cell 20, and the cylindrical battery cell 20 is accommodated in the case 10. The case 10 is used for providing an accommodating space for the cylindrical battery cell 20, and the case 10 may have various structures. In some embodiments, the case 10 may include a first portion 11 and a second portion 12, the first portion 11 and the second portion 12 being overlapped with each other, the first portion 11 and the second portion 12 together defining an accommodating space for accommodating the cylindrical battery cell 20. The second portion 12 may be a hollow structure with one end opened, the first portion 11 may be a plate-shaped structure, and the first portion 11 covers the opening side of the second portion 12, so that the first portion 11 and the second portion 12 together define a containing space; the first portion 11 and the second portion 12 may be hollow structures each having an opening at one side, and the opening side of the first portion 11 is engaged with the opening side of the second portion 12. Of course, the case 10 formed by the first portion 11 and the second portion 12 may be of various shapes, such as a cylinder, a rectangular parallelepiped, or the like.

In the battery 100, the number of the cylindrical battery cells 20 may be plural, and the plurality of the cylindrical battery cells 20 may be connected in series or parallel or in parallel, and the series-parallel refers to that the plurality of the cylindrical battery cells 20 are connected in both series and parallel. The plurality of cylindrical battery cells 20 can be directly connected in series or in parallel or in series-parallel, and then the whole body formed by the plurality of cylindrical battery cells 20 is accommodated in the box body 10; of course, the battery 100 may also be a battery module formed by connecting a plurality of cylindrical battery cells 20 in series or parallel or series-parallel connection, and a plurality of battery modules are then connected in series or parallel or series-parallel connection to form a whole and are accommodated in the case 10. The battery 100 may also include other structures, for example, the battery 100 may also include a bus member for making electrical connection between the plurality of cylindrical battery cells 20.

Wherein each of the cylindrical battery cells 20 may be a secondary battery cell or a primary battery cell; but not limited to, lithium sulfur battery cells, sodium ion battery cells, or magnesium ion battery cells.

Referring to fig. 3, fig. 4 and fig. 5, fig. 3 is a schematic structural diagram of a cylindrical battery cell 20 according to some embodiments of the present application. Fig. 4 is an exploded view of a cylindrical battery cell 20 according to some embodiments of the present application. Fig. 5 is a schematic top view of a main body 231 according to some embodiments of the present application. The embodiment of the present application provides a cylindrical battery cell 20, and the cylindrical battery cell 20 includes a case 21 and an electrode assembly 23. The housing 21 includes a first half region 211 and a second half region 212, and a portion of a middle section W of the housing 21 to one end of the housing 21 in the first direction is the first half region 211. The portion of the middle section W of the housing 21 to the other end of the housing 21 is a second half-zone 212, and the first half-zone 211 and the second half-zone 212 are each provided with at least one pressure relief mechanism 22, the pressure relief mechanism 22 being configured to open to relieve the pressure inside the cylindrical battery cell 20 when the internal pressure or temperature of the cylindrical battery cell 20 reaches a threshold value. The electrode assembly 23 is accommodated in the case 21, and the electrode assembly 23 includes a main body 231 and tabs 232, the tabs 232 being connected to the main body 231. The body portion 231 has a center hole 2311, and the center hole 2311 penetrates both ends of the body portion 231 in the first direction, and the center hole 2311 communicates with the inner space of the first half region 211 and the inner space of the second half region 212. The center hole 2311 has a diameter D and the main body 231 has an outer diameter D, satisfying the following conditions: D/D is more than or equal to 10% and less than or equal to 30%.

The cylindrical battery cell 20 is the smallest unit constituting the battery 100.

The case 21 includes an end cap 217 and a case 216, the case 216 having an accommodating space open at one end for accommodating the electrode assembly 23. An end cap 217 is connected to the housing 216 and closes the opening.

The end cap 217 refers to a member that is capped at the opening of the case 216 to isolate the internal environment of the cylindrical battery cell 20 from the external environment. Without limitation, the shape of the end cap 217 may conform to the shape of the housing 216 to mate with the housing 216. Optionally, the end cap 217 may be made of a material having a certain hardness and strength (such as an aluminum alloy), so that the end cap 217 is not easy to deform when being extruded and collided, so that the cylindrical battery cell 20 can have a higher structural strength, and the safety performance can be improved. The material of the end cap 217 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not particularly limited in the embodiment of the present application.

The case 216 is a component for fitting the end cap 217 to form the internal environment of the cylindrical battery cell 20, wherein the formed internal environment may be used to house the electrode assembly 23, the electrolyte, and other components. The housing 216 and the end cap 217 may be separate components, and an opening may be provided in the housing 216, with the end cap 217 covering the opening at the opening to create the internal environment of the cylindrical battery cell 20. It is also possible, without limitation, to integrate the end cap 217 and the housing 216, and specifically, the end cap 217 and the housing 216 may form a common joint surface before other components are put into the housing, and when it is necessary to encapsulate the inside of the housing 216, the end cap 217 is then put into place against the housing 216. The housing 216 is cylindrical. The material of the housing 216 may be various, such as copper, iron, aluminum, stainless steel, aluminum alloy, plastic, etc., which is not particularly limited in the embodiment of the present application.

The electrode assembly 23 is a component in which electrochemical reactions occur in the cylindrical battery cell 20. One or more electrode assemblies 23 may be contained within the housing 21. The electrode assembly 23 is mainly formed by winding or stacking a positive electrode sheet and a negative electrode sheet, and a separator is generally provided between the positive electrode sheet and the negative electrode sheet. The portions of the positive and negative electrode sheets having active material constitute the main body 231 of the electrode assembly 23, and the portions of the positive and negative electrode sheets having no active material constitute the tabs 232, respectively. The positive electrode tab and the negative electrode tab may be located at one end of the main body 231 together or at both ends of the main body 231. During charge and discharge of the battery 100, the positive electrode active material and the negative electrode active material react with the electrolyte.

The electrode assembly 23 has a central hole 2311, and the central hole 2311 is a through hole 2143 penetrating the body part 231 in the first direction. The center hole 2311 may be a through hole 2143 formed when the electrode assembly 23 is wound, or may be a through hole 2143 formed in other manners.

The housing 216 may be a hollow structure with one end open, or the housing 216 may be a hollow structure with opposite ends open. In embodiments where the housing 216 is open at one end, the end caps 217 may be provided one for each. In an embodiment in which the housing 216 has openings formed at opposite ends, two end caps 217 may be provided, and the two end caps 217 respectively close the two openings of the housing 216, and the two end caps 217 and the housing 216 together define a receiving space.

In some embodiments, the cylindrical battery cell 20 may further include an electrode terminal 24, the electrode terminal 24 being provided on the housing 21, the electrode terminal 24 being for electrical connection with the tab 232 of the electrode assembly 23 to input or output electrical energy of the cylindrical battery cell 20. The electrode terminal 24 may be provided on the case 216 of the case 21 or may be provided on the end cap 217 of the case 21. The electrode terminal 24 and the tab 232 may be directly connected, for example, the electrode terminal 24 and the tab 232 may be directly welded. The electrode terminal 24 and the tab 232 may be indirectly connected, for example, the electrode terminal 24 and the tab 232 may be indirectly connected through a current collecting member.

As an example, the casing 216 is a hollow structure with openings formed at opposite ends, end caps 217 are respectively provided at opposite ends of the casing 216, electrode terminals 24 are respectively provided on the end caps 217 at opposite ends of the casing 216, tabs 232 are respectively formed at opposite ends of the electrode assembly 23, the tab 232 at one end of the electrode assembly 23 is a positive tab, the tab 232 at the other end of the electrode assembly 23 is a negative tab, the electrode terminals 24 on one end cap 217 are electrically connected with the positive tab, and the electrode terminals 24 on the other end cap 217 are electrically connected with the negative tab.

The first direction is the extending direction of the center hole 2311. Generally, the first direction is the length direction of the housing 21. For a cylindrical cell 20, the first direction is the axial direction of the housing 21. Referring to fig. 3, the first direction may be the Z direction shown in fig. 3.

In the first direction, the middle section W is located at the middle position of the housing 21, and the distance from the middle section W to both ends of the housing 21 is equal. Along the first direction, the housing 21 has two opposite end surfaces, and the maximum distance between the two end surfaces is the length of the housing 21, and the distances from the middle section W to the two end surfaces are equal. If the two end surfaces of the housing 21 are flat surfaces, the length of the housing 21 is measured with the two end surfaces as a reference; if a projection or recess is formed on one or both end surfaces of the housing 21, the length of the housing 21 is measured with reference to the planar area of the end surfaces. In an embodiment in which the housing 216 is a hollow structure in which one end in the first direction is open, it is possible that the surface of the end cap 217 facing the outside of the housing 21 is one end surface of the housing 21, and the surface of the wall portion of the housing 216 opposite to the end cap 217 facing the outside of the housing 21 is the other end surface of the housing 21. In an embodiment in which the housing 216 is a hollow structure in which openings are formed at opposite ends in the first direction, one end cap 217 may be provided on a surface facing the outside of the housing 21 as one end face of the housing 21, and the other end cap 217 may be provided on the other end face of the housing 21 as the surface facing the outside of the housing 21.

The first half area 211 may be provided with one pressure release mechanism 22, or may be provided with a plurality of pressure release mechanisms 22; the second half 212 may be provided with one pressure relief mechanism 22 or may be provided with a plurality of pressure relief mechanisms 22. The pressure release mechanism 22 may be part of the housing 21 or may be a separate component from the housing 21. It will be appreciated that relief mechanism 22 provided in first half 211 is located entirely within first half 211 and relief mechanism 22 provided in second half 212 is located entirely within second half 212.

In the first direction, a portion of the body 231 is located in the first half region 211, and another portion of the body 231 is located in the second half region 212. The center hole 2311 penetrates the body portion 231 in a first direction to communicate the inner space of the first half 211 with the inner space of the second half 212.

Referring to fig. 3, 4 and 5,d, the diameter of the center hole 2311 is shown, and the diameter of the center hole 2311 passing through the winding start end and the winding axis of the positive electrode sheet can be measured as the diameter of the center hole 2311 during measurement. D represents the outer diameter of the body 231. At the time of measurement, the diameter of the winding end of the main body 231 passing through the negative electrode sheet and the winding axis may be measured as the outer diameter of the main body 231.

The ratio of the aperture of the center hole 2311 to the outer diameter of the main body 231 may be: d/d=10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, 30%, etc.

The first half area 211 and the second half area 212 of the cylindrical battery cell 20 are both provided with at least one pressure release mechanism 22, and the gas in the electrode assembly 23 can flow to the pressure release mechanism 22 located in the first half area 211 and the pressure release mechanism 22 located in the second half area 212 through the central hole 2311, so that compared with the prior art that the gas flows from one end of the casing 216 to the other end, the pressure release path is shorter, thereby facilitating rapid pressure release and reducing the risk of fire and explosion of the cylindrical battery cell 20. In addition, by making the ratio of the aperture of the center hole 2311 of the electrode assembly 23 to the outer diameter of the main body 231 greater than or equal to 10% and less than or equal to 30%, not only can the center hole 2311 of the electrode assembly 23 be larger, the remaining space in the case 21 be larger, the air pressure in the case 21 be relatively smaller, and during the pressure relief, the air can rapidly flow from the center hole 2311 to the pressure relief mechanism 22, the pressure relief rate is fast, which is advantageous in reducing the risk of firing and explosion of the cylindrical battery cell 20, in improving the reliability of the cylindrical battery cell 20, but also in enabling the cylindrical battery cell 20 to have a larger energy density.

In some embodiments, 17% < D/D.ltoreq.25%.

The ratio of the aperture of the center hole 2311 to the outer diameter of the main body 231 may be: d/d=18%, 19%, 20%, 21%, 22%, 23%, 24%, 25%, etc.

By making the ratio of the aperture of the center hole 2311 of the electrode assembly 23 to the outer diameter of the main body 231 greater than 17% and less than or equal to 25%, not only can the center hole 2311 of the electrode assembly 23 be larger, the remaining space in the housing 21 be larger, but also the air pressure in the housing 21 can be relatively smaller, and during pressure relief, air can rapidly flow from the center hole 2311 to the pressure relief mechanism 22, the pressure relief rate is faster, which is beneficial to reducing the risk of firing and explosion of the cylindrical battery cell 20, improving the reliability of the cylindrical battery cell 20, and enabling the cylindrical battery cell to have a larger energy density.

Referring to fig. 3, 4 and 5, in some embodiments, the housing 21 has a first end wall 213, a second end wall 215 and a side wall 214. The first end wall 213 is located in the first half 211 and the second end wall 215 is located in the second half 212, the first end wall 213 and the second end wall 215 being oppositely disposed in the first direction. The side wall 214 surrounds the first end wall 213 and the second end wall 215. The portion of the side wall 214 located in the first half 211 and the portion of the side wall 214 located in the second half 212 are each provided with at least one pressure relief mechanism 22.

The first end wall 213 and the second end wall 215 are two wall portions of the housing 21 that are disposed opposite in the first direction. The first end wall 213 may be an end cap 217 and the second end wall 215 may be integrally formed with the side wall 214 to form a housing 216; or the second end wall 215 may be an end cover 217, and the first end wall 213 and the side wall 214 are integrally formed to form a housing 216; it is also possible that the first end wall 213 and the second end wall 215 are both end caps 217 and the side wall 214 is a housing 216. It will be appreciated that a portion of sidewall 214 is located in first half 211 and another portion of sidewall 214 is located in second half 212. The first end wall 213 and the second end wall 215 may each be a circular plate-like structure, and the side wall 214 may be a cylindrical hollow structure.

The pressure relief mechanism 22 is disposed at the portion of the side wall 214 located in the first half area 211 and the portion of the side wall 214 located in the second half area 212, and one pressure relief mechanism 22 may be disposed at the portion of the side wall 214 located in the first half area 211, or a plurality of pressure relief mechanisms 22 may be disposed. The portion of the side wall 214 located in the second half 212 may be provided with one pressure relief mechanism 22, or may be provided with a plurality of pressure relief mechanisms 22, and the first end wall 213 and the second end wall 215 may be provided with pressure relief mechanisms 22, or may not be provided with pressure relief mechanisms 22. As an example, as shown in fig. 3, 4 and 5, the portion of the side wall 214 located in the first half 211 and the portion of the side wall 214 located in the second half 212 are each provided with a pressure relief mechanism 22, and the first end wall 213 and the second end wall 215 are not provided with pressure relief mechanisms 22.

If the pressure release mechanism 22 is disposed at the portion of the side wall 214 located in the first half area 211 and the portion of the side wall 214 located in the second half area 212, the exhaust medium inside the housing 21 can be discharged from the side wall 214 of the housing 21, so that the risk that the exhaust medium damages the external components connected to the end portion of the cylindrical battery cell 20 is reduced, which is beneficial to improving the reliability of the cylindrical battery cell 20.

Referring to fig. 3, fig. 4, fig. 6, and fig. 7, fig. 6 is a schematic front view of a sidewall 214 according to some embodiments of the present application. Fig. 7 is a cross-sectional view of the position A-A of fig. 6. In some embodiments, the portion of sidewall 214 located in first half 211 and/or the portion of sidewall 214 located in second half 212 is provided with a plurality of pressure relief mechanisms 22.

"The portion of the sidewall 214 located in the first half 211 and/or the portion of the sidewall 214 located in the second half 212 is provided with a plurality of pressure relief mechanisms 22" includes: the portion of the side wall 214 located in the first half area 211 is provided with a plurality of pressure relief mechanisms 22, the portion of the side wall 214 located in the second half area 212 is provided with a plurality of pressure relief mechanisms 22, the portion of the side wall 214 located in the first half area 211 is provided with a plurality of pressure relief mechanisms 22, and the portion of the side wall 214 located in the second half area 212 is provided with a plurality of pressure relief mechanisms 22.

Through setting up a plurality of relief mechanisms 22, when the internal pressure or the temperature of the single battery 20 of cylinder reached the threshold value, a plurality of relief mechanisms 22 can open the pressure release, and the pressure release speed is faster, is favorable to reducing the risk of single battery 20 of cylinder on fire, explosion, is favorable to promoting single battery 20 of cylinder's reliability.

Referring to fig. 3, 4, 6 and 7, in some embodiments, a plurality of pressure relief mechanisms 22 are spaced apart along the circumference of the housing 21. The plurality of pressure relief mechanisms 22 includes a first pressure relief mechanism 221 and a second pressure relief mechanism 222, the opening pressure of the first pressure relief mechanism 221 being greater than the opening pressure of the second pressure relief mechanism 222.

The circumferential direction refers to the circumferential direction of the housing 21. The circumferential direction is perpendicular to the first direction. Referring to fig. 6 and 7, the circumferential direction of the housing 21 may be the X direction shown in fig. 7. The plurality of pressure release mechanisms 22 are arranged at intervals along the circumferential direction of the housing 21.

The opening pressure of the first pressure release mechanism 221 is greater than the opening pressure of the second pressure release mechanism 222, when the pressure or the temperature in the cylindrical battery cell 20 reaches the threshold value, the first pressure release mechanism 221 is not opened, and the second pressure release mechanism 222 is opened to realize pressure release.

The opening pressure of the first pressure release mechanism 221 is greater than the opening pressure of the second pressure release mechanism 222, the anti-damage capability of the first pressure release mechanism 221 is greater than the anti-damage capability of the second pressure release mechanism 222, when the pressure or the temperature inside the casing 21 reaches a threshold value, the second pressure release mechanism 222 is opened to realize pressure release, and at this time, the first pressure release mechanism 221 is not opened. The setting of the first pressure release mechanism 221 can balance the deformation amount of the side wall 214 when the second pressure release mechanism 222 is set, so that the shape of the side wall 214 is more regular, the roundness of the side wall 214 is higher, the assembly quality of the cylindrical battery cell 20 is improved, and the reliability of the cylindrical battery cell 20 is improved.

In some embodiments, the plurality of pressure relief mechanisms 22 are evenly distributed along the circumference of the housing 21.

The phrase "the plurality of pressure release mechanisms 22 are uniformly distributed along the circumferential direction of the housing 21" means that, among the plurality of pressure release mechanisms 22, the distance between two adjacent pressure release mechanisms 22 farthest from each other is E ₁, and the distance between two adjacent pressure release mechanisms 22 closest to each other is E ₂, which satisfies the following conditions: e ₁/E₂ = 1.2, 0.8.

Alternatively, the distance between each adjacent two pressure relief mechanisms 22 is equal, i.e., E ₁/E₂ =1.

Through making a plurality of relief mechanisms 22 evenly distributed along the circumference of shell 21, like this, when setting up first relief mechanism 221 and second relief mechanism 222, the atress of lateral wall 214 is more balanced, and the shape of lateral wall 214 is more regular, and the circularity of lateral wall 214 is higher, is favorable to improving the assembly quality of cylinder battery monomer 20 to improve the reliability of cylinder battery monomer 20.

Referring to fig. 3, 4, 6 and 7, in some embodiments, the housing 21 is provided with a first score groove 2141, and the first score groove 2141 defines the first pressure relief mechanism 221. The housing 21 is provided with a second score groove 2142, the second score groove 2142 defining a second pressure relief mechanism 222. The residual thickness of the first score groove 2141 is greater than the residual thickness of the second score groove 2142.

The first score groove 2141 and the second score groove 2142 may be formed in various ways, such as, for example, stamping, milling, and the like. The first score groove 2141 and the second score groove 2142 may be disposed on a surface of the side wall 214 facing the interior of the housing 21, or may be disposed on a surface of the side wall 214 facing away from the interior of the housing 21.

The sidewall 214 has opposite inner and outer surfaces in the thickness direction, the inner surface of the sidewall 214 faces the inside of the housing 21, the outer surface of the sidewall 214 faces away from the inside of the housing 21, and the first score groove 2141 and the second score groove 2142 may be both provided on the inner surface of the sidewall 214 or may be both provided on the outer surface of the sidewall 214.

The first score groove 2141 and the second score groove 2142 may be grooves recessed from the outer surface of the side wall 214 in the thickness direction of the side wall 214, the first pressure release mechanism 221 is a portion of the side wall 214 between the inner surface and the bottom surface of the first score groove 2141, and the second pressure release mechanism 222 is a portion of the side wall 214 between the inner surface and the bottom surface of the second score groove 2142. The first score groove 2141 and the second score groove 2142 may be grooves recessed from the inner surface of the side wall 214 in the thickness direction of the side wall 214, the first pressure release mechanism 221 may be a portion of the side wall 214 between the outer surface and the bottom surface of the first score groove 2141, and the second pressure release mechanism 222 may be a portion of the side wall 214 between the outer surface and the bottom surface of the second score groove 2142.

The first score groove 2141 and the second score groove 2142 may be linear grooves extending along a linear path or annular grooves extending along a closed path.

The "residual thickness of the first score groove 2141 is greater than the residual thickness of the second score groove 2142" i.e. the thickness of the first pressure relief mechanism 221 is greater than the thickness of the second pressure relief mechanism 222.

By forming the first score groove 2141 and the second score groove 2142, the first pressure release mechanism 221 and the second pressure release mechanism 222 are formed on the housing 21, so that the first pressure release mechanism 221 and the housing 21 are integrated, and the second pressure release mechanism 222 and the housing 21 are integrated, so that the integrity is better. The residual thickness of the first score groove 2141 is greater than the residual thickness of the second score groove 2142, the anti-damage capability of the outer shell 21 at the position of the first score groove 2141 is greater than the anti-damage capability of the outer shell 21 at the position of the second score groove 2142, when the pressure or temperature inside the outer shell 21 reaches a threshold value, the side wall 214 is split along the second score groove 2142 to realize pressure relief, at this time, the side wall 214 is not split along the first score groove 2141, and the arrangement of the first score groove 2141 can balance the deformation amount of the side wall 214 when the second score groove 2142 is formed, so that the shape of the side wall 214 is more regular, the roundness of the side wall 214 is improved, the assembly quality of a single battery 100 is improved, and the reliability of the single battery 100 is improved.

Referring to fig. 3, 4, 6 and 7, in some embodiments, the depth of the first score groove 2141 is smaller than the depth of the second score groove 2142, so that the residual thickness of the first score groove 2141 is greater than the residual thickness of the second score groove 2142.

By "the depth of the first score groove 2141 is less than the depth of the second score groove 2142" is meant that the maximum depth of the first score groove 2141 is less than the minimum depth of the second score groove 2142, such that the minimum residual thickness of the first score groove 2141 is greater than the maximum residual thickness of the second score groove 2142.

The depth of the second score groove 2142 is greater than the depth of the first score groove 2141, and the residual thickness of the second score groove 2142 is less than the residual thickness of the first score. Thus, the first pressure relief mechanism 221 has a greater resistance to damage than the second pressure relief mechanism 222, and the first pressure relief mechanism 221 has a greater detonation pressure than the second pressure relief mechanism 222.

Referring to fig. 3, 4, 6 and 7, in some embodiments, the second score groove 2142 has a depth H ₁, which satisfies the following requirements: h ₁ is less than or equal to 0.01mm and less than or equal to 4.5mm.

The depth of the second score groove 2142 may be uniform, i.e., the depth of the second score groove 2142 may be equal at different locations. The depth of the second score groove 2142 may also be varied, where the maximum depth of the second score groove 2142 is less than or equal to 4.5mm and the minimum depth of the second score groove 2142 is greater than or equal to 0.01mm. At the time of measurement, a distance from the bottom surface of the second score groove 2142 to the open end of the second score groove 2142 may be measured as the depth of the second score groove 2142.

The second score groove 2142 may have a depth of H ₁,H₁ =0.01 mm, 0.05mm, 0.15mm, 0.5mm, 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 3.5mm, 4mm, 4.5mm, etc.

By making the depth of the second score groove 2142 between 0.01 and 4.5mm, the second pressure release mechanism 222 can be easily opened for pressure release, and the side wall 214 can have sufficient strength.

Referring to fig. 3, 4, 6 and 7, in some embodiments, the second score groove 2142 has a groove width D ₁, which satisfies the following requirements: d ₁ is more than or equal to 0.01mm and less than or equal to 100mm.

The groove width of the second score groove 2142 may be uniform, i.e., the groove widths of the second score grooves 2142 may be equal at different locations. The groove width of the second score groove 2142 may also be varied, in which case the maximum groove width of the second score groove 2142 is less than or equal to 100mm and the minimum groove width of the second score groove 2142 is greater than or equal to 0.01mm. At the time of measurement, the width of the open end of the second score groove 2142 may be measured as the depth of the second score groove 2142.

The second score groove 2142 may have a groove width D₁,D₁＝0.01mm、0.05mm、0.15mm、0.5mm、1mm、1.5mm、2mm、2.5mm、3mm、10mm、15mm、25mm、50mm、75mm、100mm or the like.

By making the groove width of the second score groove 2142 between 0.01 and 100mm, the second pressure release mechanism 222 can be easily opened for pressure release, and the side wall 214 can be made to have sufficient strength. In addition, the second score groove 2142 has a larger groove width, so that a larger opening can be opened, thereby facilitating rapid pressure release and improving the reliability of the cylindrical battery cell 20.

Referring to fig. 3, 4, 6 and 7, in some embodiments, along the extending direction of the second score groove 2142, the length of the second score groove 2142 is L ₁, which satisfies the following requirements: l ₁ mm to 250mm.

L ₁ denotes the length of the second score groove 2142 along the extension direction of the second score groove 2142. For example, when the second score groove 2142 extends along a straight track, the length of the second score groove 2142 is the length along the straight track. As another example, when the second score groove 2142 extends along the circular arc track, the length of the second score groove 2142 is the length along the circular arc track.

Along the extending direction of the second score groove 2142, the length of the second score groove 2142 may be: l ₁ = 1mm, 1.5mm, 2mm, 2.5mm, 3mm, 10mm, 15mm, 25mm, 50mm, 75mm, 100mm, 150mm, 200mm, 250mm, etc.

By making the length of the second score groove 2142 between 1 and 250mm, the second pressure release mechanism 222 can be easily opened for pressure release, and the side wall 214 can be made to have sufficient strength. In addition, the second score groove 2142 has a larger length, and can open a larger opening, so as to facilitate rapid pressure release and improve the reliability of the cylindrical battery cell 20.

Referring to fig. 3, 4, 6 and 7, in some embodiments, the second score groove 2142 has a volume V ₁, the outer surface of the sidewall 214 has a volume V ₂, and the inner surface of the sidewall 214 has a volume V ₃, which satisfies the following requirements: v ₁/(V₂-V₃) is less than or equal to 0.1.

V ₁ denotes the volume of the second score groove 2142. For example, V ₁＝D₁*L₁*H₁ when the second score groove 2142 is rectangular in cross section perpendicular to its extension.

V ₂ represents the volume of the outer surface of the sidewall 214, the outer diameter of the sidewall 214 is R ₂, the length of the sidewall 214 is L ₃, and V ₂＝L₃*π(R₂)².

V ₃ denotes the volume of the inner surface of the side wall 214, the inner diameter of the side wall 214 is R ₁, the length of the side wall 214 is L ₃, and V ₃＝L₃*π(R₁)² is present.

V ₁/(V₂-V₃) may take the value of; v ₁/(V₂-V₃) =0.1, 0.09, 0.08, 0.07, 0.06, 0.05, 0.04, 0.03, 0.02, 0.01, and the like.

By making V1/(V2-V3). Ltoreq.0.1, the case 21 has higher strength, the electrode assembly 23 in the case 21 can be effectively protected, and the second pressure release mechanism 222 is not easily opened by mistake when external impact is received, thereby improving the reliability of the cylindrical battery cell 20.

Referring to fig. 3, 4, 6 and 7, in some embodiments, the housing 21 is provided with a second score groove 2142, and the second score groove 2142 defines the second pressure relief mechanism 222. The minimum residual thickness of the second score groove 2142 is C ₁ and the thickness of the sidewall 214 is C ₂, satisfying: c ₁/C₂ is more than or equal to 0.1 and less than or equal to 0.9.

C ₁ represents the minimum thickness of the sidewall 214 remaining after the second score groove 2142 is provided, i.e., the minimum thickness of the second pressure relief mechanism 222. C ₂ denotes the thickness of the side wall 214. The ratio of the minimum residual thickness of the second score groove 2142 to the thickness of the sidewall 214 is between 0.1 and 0.9.

The ratio of the minimum residual thickness of the second score groove 2142 to the thickness of the sidewall 214 may be: c ₁/C₂ = 0.1, 0.2, 0.3, 0.4, 0.5, 0.6, 0.7, 0.8, 0.9, etc.

By making the ratio of the minimum residual thickness of the second score groove 2142 to the residual thickness of the side wall 214 between 0.1 and 0.9, the second pressure release mechanism 222 can be easily opened for pressure release, and the side wall 214 can be made sufficiently strong.

In some embodiments, 0.3C ₁/C₂ C0.7.

The ratio of the minimum residual thickness of the second score groove 2142 to the thickness of the sidewall 214 may be: c ₁/C₂ = 0.3, 0.35, 0.4, 0.45, 0.5, 0.55, 0.6, 0.65, 0.7, etc.

By having 0.3C ₁/C₂ C0.7, the strength of the side wall 214 is better and the second pressure relief mechanism 222 is less prone to false opening under external forces.

Referring to fig. 3, 4, 6 and 7, in some embodiments, the first pressure relief mechanism 221 and the second pressure relief mechanism 222 are alternately arranged along the circumferential direction of the housing 21.

Along the circumference of the housing 21, a second pressure release mechanism 222 is provided between the two first pressure release mechanisms 221, and a first pressure release mechanism 221 is provided between the two second pressure release mechanisms 222.

By alternately arranging the first pressure release mechanism 221 and the second pressure release mechanism 222 in the circumferential direction of the casing 21, when the first pressure release mechanism 221 and the second pressure release mechanism 222 are arranged, the stress of the side wall 214 is more uniform, which is beneficial to keeping the shape rule of the side wall 214, and the roundness of the side wall 214 is higher.

Referring to fig. 3, 4, 6 and 7, in some embodiments, in the first direction, the minimum distance between the pressure release mechanism 22 and the end of the housing 21 closer to the pressure release mechanism 22 is L ₂, and the length of the housing 21 is L ₃, which satisfies the following requirements: l ₂/L₃ is more than or equal to 0.3.

The pressure relief mechanism 22 is provided in a side wall 214 of the housing 21, the housing 21 having a first end wall 213 and a second end wall 215. The pressure relief mechanism 22 is at a minimum distance L ₂ from the closer one of the first end wall 213 and the second end wall 215.

The value of L ₂/L₃ may be: l ₂/L₃ = 0.3, 0.31, 0.32, 0.33, 0.34, 0.35, 0.36, 0.37, 0.38, 0.39, 0.4, 0.45, etc.

By making the minimum distance between the pressure release mechanism 22 and the end of the housing 21 closer to the pressure release mechanism 22 be greater than or equal to 0.3 times the length of the housing 216, the distance between the pressure release mechanism 22 and the end of the housing 21 is greater, and the roundness of the end of the pressure release mechanism 22 is not easily affected when the pressure release mechanism 22 is provided, thereby facilitating improvement of the assembly quality of the cylindrical battery cell 20 and improving the reliability of the cylindrical battery cell 20.

Referring to fig. 8 and 9, fig. 8 is a schematic front view of a sidewall 214 according to other embodiments of the present application. Fig. 9 is a cross-sectional view of the B-B position of fig. 8. In some embodiments, the housing 21 is provided with a through hole 2143, and the pressure release mechanism 22 is mounted to the housing 21 and seals the through hole 2143.

The pressure release mechanism 22 may be provided separately from and connected to the housing 21, and the pressure release mechanism 22 blocks the through hole 2143. When the internal pressure of the cylindrical battery cell 20 reaches a threshold, the pressure relief mechanism 22 can be opened, thereby effecting pressure relief.

When the cylindrical battery cell 20 is out of control, the pressure release mechanism 22 will open the through hole 2143 under the action of the air pressure or the high-temperature air of the cylindrical battery cell 20, so as to allow the air in the cylindrical battery cell 20 to exit the housing 21, thereby realizing pressure release.

Referring to fig. 8 and 9, in some embodiments, the pressure release mechanism 22 is a filling layer 2144 filled in the through hole 2143.

The filling layer 2144 can seal the through hole 2143, prevent gas in the cylindrical battery cell 20 from leaving the cylindrical battery cell 20, and prevent external moisture from entering the cylindrical battery cell 20.

In some embodiments, the filler layer 2144 is capable of opening under the influence of air pressure inside the cylindrical battery cell 20. In other embodiments, the filler layer 2144 is capable of melting under the effect of high temperature gases generated when the cylindrical battery cell 20 is thermally out of control, thereby opening the through hole 2143, allowing the cylindrical battery cell 20 to decompress.

When the cylindrical battery cell 20 is out of control, the filling layer 2144 will open the through hole 2143 under the action of the air pressure or high temperature air of the cylindrical battery cell 20, thereby allowing the air in the cylindrical battery cell 20 to exit the housing 21, and realizing pressure relief.

Referring to fig. 6 and 7, in some embodiments, along the circumference of the housing 21, the maximum size of the pressure relief mechanism 22 is D ₂, and the circumference of the housing 21 is N, so that: d ₂/N is more than or equal to 5% and less than or equal to 25%.

D ₂ denotes the maximum size of the pressure release mechanism 22 in the circumferential direction of the casing 21, that is, the distance from one end to the other end of the pressure release mechanism 22 in the circumferential direction of the casing 21.

The ratio of the maximum dimension of the pressure release mechanism 22 in the circumferential direction of the casing 21 to the circumferential length of the casing 21 may be: d ₂/n=5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, etc.

By limiting the maximum size of the pressure release mechanism 22 in the circumferential direction of the housing 21 to 0.05 to 0.25 times the circumferential length of the housing 21, the pressure release mechanism 22 can be conveniently machined, and the machined pressure release mechanism 22 can be easily opened for pressure release, so that the housing 21 has sufficient strength.

Referring to fig. 6 and 7, in some embodiments, in the first direction, the maximum size of the pressure relief mechanism 22 is L ₄, and the length of the housing 21 is L ₃, which satisfies the following requirements: l ₄/L₃% to 25%.

L ₄ denotes the maximum dimension of the pressure relief mechanism 22 in the first direction, i.e. the distance from one end of the pressure relief mechanism 22 to the other end in the first direction.

The ratio of the maximum dimension of the pressure relief mechanism 22 in the first direction to the length of the housing 21 may be: l ₄/L₃ = 5%, 8%, 10%, 12%, 15%, 18%, 20%, 22%, 25%, etc.

Through limiting the maximum size of the pressure release mechanism 22 along the first direction to 0.05-0.25 times of the length of the shell 21, the pressure release mechanism 22 can be opened easily, the shell 21 can have enough strength, and the opening opened when the pressure release mechanism 22 releases pressure is larger, so that quick pressure release is realized.

In some embodiments, electrode assembly 23 is a rolled electrode assembly.

The winding type electrode assembly is formed by winding a positive electrode plate, a separation film and a negative electrode plate.

Since the wound electrode assembly relies more on the center hole 2311 than the laminated electrode assembly in pressure relief, the pressure relief effect is better for the wound electrode assembly by making the ratio of the aperture of the center hole 2311 of the electrode assembly 23 to the outer diameter of the main body 231 greater than or equal to 10%.

The embodiment of the application also provides a battery 100, wherein the battery 100 comprises the cylindrical battery cell 20 in any one of the above.

The embodiment of the application also provides electric equipment, which comprises the cylindrical battery monomer 20 in any one of the above.

According to some embodiments of the application, please refer to fig. 3-7.

The embodiment of the present application provides a cylindrical battery cell 20, and the cylindrical battery cell 20 includes a case 21 and an electrode assembly 23. The housing 21 includes a first half area 211 and a second half area 212, and a portion of a middle section W of the housing 21 to one end of the housing 21 is the first half area 211 and a portion of a middle section W of the housing 21 to the other end of the housing 21 is the second half area 212 in the first direction. The first half 211 and the second half 212 are each provided with at least one pressure relief mechanism 22, the pressure relief mechanism 22 being configured to open when the internal pressure or temperature of the cylindrical battery cell 20 reaches a threshold value to relieve the pressure inside the cylindrical battery cell 20. The electrode assembly 23 is accommodated in the case 21, and the electrode assembly 23 includes a main body 231 and tabs 232, the tabs 232 being connected to the main body 231. The body portion 231 has a center hole 2311, and the center hole 2311 penetrates both ends of the body portion 231 in the first direction, and the center hole 2311 communicates with the inner space of the first half region 211 and the inner space of the second half region 212. The center hole 2311 has a diameter D and the main body 231 has an outer diameter D, satisfying the following conditions: D/D is more than or equal to 10% and less than or equal to 30%. The first half area 211 and the second half area 212 of the cylindrical battery cell 20 are both provided with at least one pressure release mechanism 22, and the gas in the electrode assembly 23 can flow to the pressure release mechanism 22 located in the first half area 211 and the pressure release mechanism 22 located in the second half area 212 through the central hole 2311, so that compared with the prior art that the gas flows from one end of the casing 216 to the other end, the pressure release path is shorter, thereby facilitating rapid pressure release and reducing the risk of fire and explosion of the cylindrical battery cell 20. In addition, by making the ratio of the aperture of the center hole of the electrode assembly 23 to the outer diameter of the main body 231 greater than or equal to 10% and less than or equal to 30%, not only can the center hole 2311 of the electrode assembly 23 be larger, the remaining space in the housing 21 be larger, the air pressure in the housing 21 can be relatively smaller, and during the pressure release, the air can rapidly flow from the center hole 2311 to the pressure release mechanism 22, the pressure release rate is fast, which is advantageous in reducing the risk of firing and explosion of the cylindrical battery cell 20, in improving the reliability of the cylindrical battery cell 20, but also in enabling the cylindrical battery cell 20 to have a larger energy density.

17% < D/d.ltoreq.25%, by making the ratio of the aperture of the center hole of the electrode assembly 23 to the outer diameter of the main body portion 231 greater than 17% and less than or equal to 25%, not only can the center hole 2311 be made larger, which is advantageous for improving the pressure release rate, improving the reliability of the cylindrical battery cell 20, but also can make the cylindrical battery cell 20 have a larger energy density.

The housing 21 has a first end wall 213, a second end wall 215 and a side wall 214, the first end wall 213 being located in the first half 211 and the second end wall 215 being located in the second half 212. The first end wall 213 and the second end wall 215 are disposed opposite to each other in the first direction, and the side wall 214 is provided around the first end wall 213 and the second end wall 215. The portion of the side wall 214 located in the first half 211 and the portion of the side wall 214 located in the second half 212 are each provided with at least one pressure relief mechanism 22. If the pressure release mechanism 22 is disposed at the portion of the side wall 214 located in the first half area 211 and the portion of the side wall 214 located in the second half area 212, the exhaust medium inside the housing 21 can be discharged from the side wall 214 of the housing 21, so that the risk that the exhaust medium damages the external components connected to the end portion of the cylindrical battery cell 20 is reduced, which is beneficial to improving the reliability of the cylindrical battery cell 20.

The portion of the side wall 214 located in the first half 211 and/or the portion of the side wall 214 located in the second half 212 is provided with a plurality of pressure relief mechanisms 22, the plurality of pressure relief mechanisms 22 being spaced apart along the circumferential direction of the housing 21. The plurality of pressure relief mechanisms 22 includes a first pressure relief mechanism 221 and a second pressure relief mechanism 222, the detonation pressure of the first pressure relief mechanism 221 being greater than the detonation pressure of the second pressure relief mechanism 222. The second pressure relief mechanism 222 is configured to open a pressure relief when the cylindrical battery cell 20 is thermally out of control. The detonation pressure of the first pressure release mechanism 221 is greater than the detonation pressure of the second pressure release mechanism 222, the anti-damage capability of the first pressure release mechanism 221 is greater than the anti-damage capability of the second pressure release mechanism 222, when the pressure or temperature inside the casing 21 reaches a threshold value, the second pressure release mechanism 222 is opened to realize pressure release, and at this time, the first pressure release mechanism 221 is not opened. The setting of the first pressure release mechanism 221 can balance the deformation amount of the side wall 214 when the second pressure release mechanism 222 is set, so that the shape of the side wall 214 is more regular, the roundness of the side wall 214 is higher, the assembly quality of the cylindrical battery cell 20 is improved, and the reliability of the cylindrical battery cell 20 is improved.

The above description is only of the preferred embodiments of the present application and is not intended to limit the present application, but various modifications and variations can be made to the present application by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included in the protection scope of the present application.

Claims

1. A cylindrical battery cell, comprising:

The shell comprises a first half area and a second half area, the part from the middle section of the shell to one end of the shell is the first half area, the part from the middle section of the shell to the other end of the shell is the second half area, and the first half area and the second half area are respectively provided with at least one pressure relief mechanism, and the pressure relief mechanisms are configured to be opened when the internal pressure or the temperature of the cylindrical battery cell reaches a threshold value so as to relieve the internal pressure of the cylindrical battery cell;

the electrode assembly is contained in the shell, the electrode assembly comprises a main body part and a tab, the tab is connected to the main body part, the main body part is provided with a central hole, the central hole penetrates through two ends of the main body part along the first direction, the central hole is communicated with the inner space of the first half area and the inner space of the second half area, the aperture of the central hole is D, the outer diameter of the main body part is D, and the requirements are met: D/D is more than or equal to 10% and less than or equal to 30%.

2. The cylindrical battery cell according to claim 1, wherein 17% < D/d.ltoreq.25%.

3. The cylindrical battery cell of claim 1, wherein the housing has a first end wall, a second end wall, and a side wall, the first end wall being located in the first half and the second end wall being located in the second half, the first end wall and the second end wall being disposed opposite in the first direction, the side wall surrounding the first end wall and the second end wall;

The part of the side wall located in the first half area and the part of the side wall located in the second half area are both provided with at least one pressure relief mechanism.

4. A cylindrical battery cell according to claim 3, wherein the portion of the side wall located in the first half and/or the portion of the side wall located in the second half is provided with a plurality of said pressure relief mechanisms.

5. The cylindrical battery cell of claim 4, wherein a plurality of the pressure relief mechanisms are circumferentially spaced apart along the housing, the plurality of pressure relief mechanisms comprising a first pressure relief mechanism and a second pressure relief mechanism, the first pressure relief mechanism having a cracking pressure greater than a cracking pressure of the second pressure relief mechanism.

6. The cylindrical battery cell as recited in claim 5, wherein a plurality of the pressure relief mechanisms are evenly distributed along a circumference of the housing.

7. The cylindrical battery cell of claim 5, wherein the housing is provided with a first score groove defining the first pressure relief mechanism;

the housing is provided with a second score groove defining the second pressure relief mechanism, the residual thickness of the first score groove being greater than the residual thickness of the second score groove.

8. The cylindrical battery cell of claim 7, wherein the depth of the first score groove is less than the depth of the second score groove such that the residual thickness of the first score groove is greater than the residual thickness of the second score groove.

9. The cylindrical battery cell of claim 7, wherein the second score groove has a depth H ₁ that satisfies: h ₁ is more than or equal to 0.01mm and less than or equal to 4.5mm; and/or, the groove width of the second notch groove is D ₁, which satisfies the following conditions: d ₁ is more than or equal to 0.01mm and less than or equal to 100mm; and/or, along the extending direction of the second score groove, the length of the second score groove is L ₁, which satisfies the following conditions: l ₁ mm to 250mm.

10. The cylindrical battery cell of claim 7, wherein the second score groove has a volume V ₁, the outer surface of the sidewall has a volume V ₂, and the inner surface of the sidewall has a volume V ₃, satisfying: v ₁/(V₂-V₃) is less than or equal to 0.1.

11. The cylindrical battery cell of claim 7, wherein the housing is provided with a second score groove defining the second pressure relief mechanism, the second score groove having a minimum residual thickness of C ₁, and the sidewall having a thickness of C ₂, satisfying: c ₁/C₂ is more than or equal to 0.1 and less than or equal to 0.9.

12. The cylindrical battery cell of claim 11, wherein 0.3 +.c ₁/C₂ +.0.7.

13. The cylindrical battery cell as recited in claim 5, wherein the first pressure relief mechanism and the second pressure relief mechanism alternate along a circumferential direction of the housing.

14. The cylindrical battery cell of claim 1, wherein in the first direction, a minimum distance between the pressure relief mechanism and an end of the housing closer to the pressure relief mechanism is L ₂, and a length of the housing is L ₃, such that: l ₂/L₃ is more than or equal to 0.3.

15. The cylindrical battery cell as recited in claim 1, wherein the housing is provided with a through hole, and the pressure relief mechanism is mounted to the housing and blocks the through hole.

16. The cylindrical battery cell as recited in claim 15, wherein the pressure relief mechanism is a fill layer filled within the through hole.

17. The cylindrical battery cell according to any one of claims 1-16, wherein the maximum dimension of the pressure relief mechanism along the circumference of the housing is D ₂, and the circumference of the housing is N, satisfying: d ₂/N is more than or equal to 5% and less than or equal to 25%.

18. The cylindrical battery cell according to any one of claims 1-16, wherein in the first direction, the pressure relief mechanism has a maximum dimension L ₄ and the housing has a length L ₃, satisfying: l ₄/L₃% to 25%.

19. A battery comprising a cylindrical cell according to any one of claims 1-18.

20. A powered device comprising a cylindrical battery cell according to any one of claims 1-18.